Failed mobo, or so I thought.

For some reason when I booted up ny PC, I got no POST - just a blank
screen. The fans were working and I could hear the hdd spinning up and
the mobo had its diode light on, but nothing else. I removed all
components, including memory modules apart from processor and fans,
but still nothing happened, no beeps, not even a memory error
showing. After scratching my head and assuming a mobo failure, I
removed the BIOS battery as a last ditch attempt. When switching on I
then got a series of nasty repetitive clicks, as the machine tried to
boot up. I switched off, replaced the battery and switched on again.
Then at last a POST showing memory failure. I replaced the memory
modules, graphics card and hdd. Finally my PC is back to normal.

The problem occurred after the machine went in to Standby on S3 (ie it
was in hibernation). When I hit the power switch most time it boots up
fine, but occasionally there are problems. So why did I need to reset
the BIOS, and does Stanby/Hibernation cause this kind of problem?

On Mon, 04 Jun 2007 15:00:03 -0700, Frank Booth Snr
<fbsnr.TakeThisOut@yahoo.co.uk> wrote:

>For some reason when I booted up ny PC, I got no POST - just a blank
>screen. The fans were working and I could hear the hdd spinning up and
>the mobo had its diode light on, but nothing else. I removed all
>components, including memory modules apart from processor and fans,
>but still nothing happened, no beeps, not even a memory error
>showing. After scratching my head and assuming a mobo failure, I
>removed the BIOS battery as a last ditch attempt. When switching on I
>then got a series of nasty repetitive clicks, as the machine tried to
>boot up. I switched off, replaced the battery and switched on again.
>Then at last a POST showing memory failure. I replaced the memory
>modules, graphics card and hdd. Finally my PC is back to normal.
>
>The problem occurred after the machine went in to Standby on S3 (ie it
>was in hibernation). When I hit the power switch most time it boots up
>fine, but occasionally there are problems. So why did I need to reset
>the BIOS, and does Stanby/Hibernation cause this kind of problem?


I'd wonder if your power supply has a failing or inadequate
5VSB circuit. If your board is jumpered to use 5VSB for PS2
or USB, you might try changing that from 5VSB to 5V, it
should be shown in the motherboard manual.

Did you try only unplugging the PSU from AC for a couple
minutes? If not try that next time.